The objective of this research proposal is to investigate the effects of acute metabolic conditions, namely, hypoxia, acidosis, hypoglycemia, hypernatremia, and hyperbilirubinemia, during the early postnatal period on central nervous system development, organization, and function. Recordings will be made of sensory function in the visual and auditory modalities, sleep organization, and EEG maturation of infants in study and control groups. The purpose is to (a) evaluate the extent to which selected metabolic abnormalities may distort the neurophysiological responses of the newborn infant and to (b) evaluate the effect of acute metabolic change in the newborn on subsequent neurological and behavioral development during early infancy.